Fix opencv#8093: CV_DbgAssert that the result of area() fits in the return value

reunanen · reunanen · commit f3cb5084cf1e · 2017-01-31T15:02:36.000+02:00
diff --git a/modules/core/include/opencv2/core/types.hpp b/modules/core/include/opencv2/core/types.hpp
@@ -1592,7 +1592,10 @@ Size_<_Tp>& Size_<_Tp>::operator = (const Size_<_Tp>& sz)
 template<typename _Tp> inline
 _Tp Size_<_Tp>::area() const
 {
-    return width * height;
+    const _Tp result = width * height;
+    CV_DbgAssert(!std::numeric_limits<_Tp>::is_integer
+        || width == 0 || result / width == height); // make sure the result fits in the return value
+    return result;
 }
 
 template<typename _Tp> static inline
@@ -1731,7 +1734,10 @@ Size_<_Tp> Rect_<_Tp>::size() const
 template<typename _Tp> inline
 _Tp Rect_<_Tp>::area() const
 {
-    return width * height;
+    const _Tp result = width * height;
+    CV_DbgAssert(!std::numeric_limits<_Tp>::is_integer
+        || width == 0 || result / width == height); // make sure the result fits in the return value
+    return result;
 }
 
 template<typename _Tp> template<typename _Tp2> inline

Original file line number	Diff line number	Diff line change
`@@ -1592,7 +1592,10 @@ Size_<_Tp>& Size_<_Tp>::operator = (const Size_<_Tp>& sz)`
`1592`	`1592`	`template<typename _Tp> inline`
`1593`	`1593`	`_Tp Size_<_Tp>::area() const`
`1594`	`1594`	`{`
`1595`		`- return width * height;`
	`1595`	`+ const _Tp result = width * height;`
	`1596`	`+ CV_DbgAssert(!std::numeric_limits<_Tp>::is_integer`
	`1597`	`+ \|\| width == 0 \|\| result / width == height); // make sure the result fits in the return value`
	`1598`	`+ return result;`
`1596`	`1599`	`}`
`1597`	`1600`
`1598`	`1601`	`template<typename _Tp> static inline`
`@@ -1731,7 +1734,10 @@ Size_<_Tp> Rect_<_Tp>::size() const`
`1731`	`1734`	`template<typename _Tp> inline`
`1732`	`1735`	`_Tp Rect_<_Tp>::area() const`
`1733`	`1736`	`{`
`1734`		`- return width * height;`
	`1737`	`+ const _Tp result = width * height;`
	`1738`	`+ CV_DbgAssert(!std::numeric_limits<_Tp>::is_integer`
	`1739`	`+ \|\| width == 0 \|\| result / width == height); // make sure the result fits in the return value`
	`1740`	`+ return result;`
`1735`	`1741`	`}`
`1736`	`1742`
`1737`	`1743`	`template<typename _Tp> template<typename _Tp2> inline`